This invention relates to ordnance and more particularly to armor penetrating projectiles.
In order to increase the offensive capability of light armored vehicles, the U.S. Marine Corps can either increase the size of the weapons systems on such vehicles or the penetration capability of the projectiles of existing systems. Since the expense of replacing existing 0.50 caliber weapons systems with systems possessing larger guns is great, there is considerable interest in developing a more effective 0.50 caliber machine gun bullet. The problem can be approached from several aspects: improved materials, more efficient penetration mechanisms, higher impact velocities, etc. Among the most promising new materials are metal matrix composites (MMC).
It was the severe operating conditions subjected on space age components for the aerospace industry which resulted in the development of composite materials science as we know it. Up until this time, the vast majority of composite development has been in the field of structural materials. In particular, materials with high strength, high stiffness, low density and elevated operating temperatures have been sought. More recently, scientists and engineers have recognized the advantages of applying MMC technology for other than structural applications. In such applications, physical, chemical, electrical, magnetic and other nonstructural properties may be of importance.
In the field of military ordnance, in addition to the importance of normal engineering structural properties of materials, we are concerned with high strain rate effects and shock wave interactions between composite components. The failure mechanisms of composite munitions will undoubtably be different than for those fabricated by homogeneous materials. A study of failure mechanisms in ballistic penetrators may yield information useful in designing both more efficient penetrators and better armors to defeat these penetrators.
Composite materials used for aerospace applications have been, for the most part, low in quantity and high in cost. For conventional ordnance applications, the material cost is frequently of prime importance, and significant improvement must be demonstrated to justify even modest cost increases. As a result, it is important to develop inexpensive fabrication techniques for composite material ordnance. The most feasible of these would be simple modifications of existing casting, powder metallurgy, extrusion, etc. techniques currently used for fabricating homogeneous metals.